Zoology and wildlife conservation

The B-cell-specific transcription coactivator OCA-B/OBF-1/Bob-1 is essential for normal production of immunoglobulin isotypes

Article Abstract:

Mice lacking in the single polypeptide OCA-B were generated through gene targeting to determine the biological role of OCA-B. Mice deficient with OCA-B undergo normal antigen-independent, B-cell differentiation. Antigen-dependent maturation of B cells is highly affected, however. Weak proliferative response to surface IgM crosslinking is noted, as well a severe deficiency in the production of secondary immunoglobulin isotypes in OCA-B-deficient B cells. Germinal center formation is not found in these mutant mice.

Secondary V(D)J recombination in B-1 cells

Article Abstract:

The self-renewing B-1 B cells are predisposed to auto-antibody production. B-1 cells are shown to express recombinase-activating genes 1 and 2, undergoing secondary V(D)J recombination of immunoglobulin genes. High levels of RAG messenger RNA and recombination were observed in B cells from autoimmune-prone NZB mice. The secondary immunoglobulin-gene rearrangements may have a role in the development of autoreactive antibodies.

Continued RAG expression in late stages of B Cell development and no apparent re-induction after immunization

Article Abstract:

The regulation of RAG expression in transgenic mice with a bacterial artificial chromosome encoding a green fluorescent protein report instead of RAG2 was investigated. The reporter was found to be expressed in all immature B cells in the bone marrow and spleen. Endogenous RAG messenger RNA is expressed in immature B cells, decreasing as they acquire higher rates of surface immunoglobulin M.